In beam performances of the MIMOSIS-2.1 CMOS Monolithic Active Pixel Sensor

TL;DR

This paper presents the MIMOSIS-2.1 CMOS Monolithic Active Pixel Sensor prototype, highlighting its improved features, radiation tolerance, and beam test performance for high-energy physics experiments.

Contribution

Introduction of the MIMOSIS-2.1 sensor with on-chip grouping circuits, improved analog power grid, and a new 50 μm epitaxial layer enhancing non-irradiated performance.

Findings

Sensor achieves 5 μm spatial precision and 5 μs time resolution.

Demonstrates robustness under high radiation doses and fluences.

Beam tests at CERN-SPS validate sensor performance.

Abstract

MIMOSIS is a CMOS Monolithic Active Pixel Sensor developed to equip the Micro Vertex Detector of the Compressed Baryonic Matter (CBM) experiment at FAIR/GSI. The sensor will combine an excellent spatial precision of $5~\mu m$ with a time resolution of $5~\mu s$ and provide a peak hit rate capability of $\mathrm{\sim 80~ MHz/cm^2}$. To fulfill its task, MIMOSIS will have to withstand ionising radiation doses of $\sim 5~ \mathrm{MRad}$ and fluences of $\sim 7 \times 10^{13}~\mathrm{n_{eq}/cm^2}$ per year of operation. This paper introduces the reticle size full feature sensor prototype MIMOSIS-2.1, which was improved with respect to earlier prototypes by adding on-chip grouping circuts and by improving the analog power grid. Moreover, it features for a first time a $50~\mu m$ epitaxial layer, which is found to improve the performances of the non-irradiated device significantly. We discuss the in beam sensor performances as measured during beam tests at the CERN-SPS.